Extra Pulse Research Articles

Stepwise Growth of Crystalline MoS2 in Atomic Layer Deposition

Transition metal dichalcogenides (TMDCs) are layered materials in which each layer is weakly bound by van der Waals forces. TMDCs have interesting intrinsic properties, including high mobility and excellent electrostatic controllability, even at monolayer thickness. Hence, they have emerged as promising materials for widespread applications in nanoelectronics, optoelectronics, gas sensors, etc. The aforementioned properties of TMDCs are significantly affected by the structuralquality and crystallinity. Accordingly, scalable techniques have been sought for synthesizing well-crystallized TMDCs.Atomic layer deposition (ALD) is considered a promising growth technique for transition metal dichalcogenides (TMDCs) because it ensures uniformity and homogeneity of the TMDC grains. However, the poor crystallinity of ALD-grown TMDCs remains a critical challenge. Although crystallinity depends on the growth mechanism, the growth behavior of crystalline TMDCs in ALD is unclear. We investigated the growth behavior of highly crystallized molybdenum disulfide (MoS2) by ALD at 650 oC with an extra pulse of remote H2 plasma. Growth at high temperatures using the activated species aided surface diffusion of the adsorbates. The ALD process facilitates repeated growth and saturation of MoS2, unlike the normal ALD of 3D bulk materials, where the film thickness monotonically increases with the number of ALD cycles. This unique behavior resulted from the evolution of the basal plane without dangling bonds. On the basal plane, MoS2 lateral growth dominates vertical growth, and prolonged incubation is required for nucleation on the basal plane. The grain size is small (up to two monolayers) because of the limited mobility on SiO2, and the grains of the third layer grow to a few hundred nanometers. These findings provide insights into the development of ALD technology for application to high-quality TMDCs.

Impact of pulsed field ablation on intraluminal esophageal temperature.

Atrio-esophageal fistula after esophageal thermal injury (ETI) is one of the most devastating complications of available energy sources for atrial fibrillation (AF) ablation. Pulsed field ablation (PFA) uses electroporation as a new energy source for catheter ablation with promising periprocedural safety advantages over existing methods due to its unique myocardial tissue sensitivity. In preclinical animal studies, a dose-dependent esophageal temperature rise has been reported. In the TESO-PFA registry intraluminal esophageal temperature (TESO) changes in a clinical setting are evaluated. Consecutive symptomatic AF patients (62 years, 67% male, 61% paroxysmal AF, CHA2 DS2 Vasc Score 2) underwent first-time PFA and were prospectively enrolled into our registry. Eight pulse trains (2 kV/2.5 s, bipolar, biphasic, x4 basket/flower configuration each) were delivered to each pulmonary vein (PV). Two extra pulse trains per PV in flower configuration were added for wide antral circumferential ablation. Continuous intraluminal esophageal temperature (TESO) was monitored with a 12-pole temperature probe. Median TESO change was statistically significant and increased by 0.8 ± 0.6°C, p < .001. A TESO increase ≥ 1°C was observed in 10/43 (23%) patients. The highest TESO measured was 40.3°C. The largest TESO difference (∆TESO) was 3.7°C. All patients remained asymptomatic considering possible ETI. No atrio-esophageal fistula was reported on follow-up. A small but significant intraluminal esophageal temperature rise can be observed in most patients during PFA. TESO rise over 40°C is rare. The clinical implications of the observed findings need to be further evaluated.

Wide antral circumferential vs. ostial pulmonary vein isolation using pulsed field ablation-the butterfly effect.

Wide antral circumferential ablation (WACA) in comparison to ostial pulmonary vein (PV) isolation (PVI) has been attributed with improved rhythm outcome. We investigated the feasibility, lesion formation, and rhythm outcome of WACA-PVI in comparison to ostial-PVI using pulsed field ablation (PFA). Symptomatic atrial fibrillation (AF) patients (69 years, 67% male; 67% paroxysmal AF) were prospectively enrolled into our single-center registry and underwent first-time ostial-PFA or WACA-PFA, N = 15 each. In all patients, eight pulse trains (2 kV/2.5 s, bipolar, biphasic, 4× basket/flower configuration each) were delivered to each PV. In WACA-PFA, two extra pulse trains in a flower configuration were added to the anterior and posterior antrum of the PVs. For comparison of PFA lesion size, pre- and post-ablation left atrial (LA) voltage maps were acquired using a multipolar spiral catheter together with a three-dimensional electroanatomic mapping system. WACA-PFA resulted in a significant larger lesion formation than ostial-PFA (45.5 vs. 35.1 cm2, p = 0.001) with bilateral overlapping butterfly shape-like lesions and concomitant posterior LA wall isolation in 73% of patients. This was not associated with increased procedure time, sedation dosage, or exposure to radiation. One-year freedom from AF recurrence was numerically higher after WACA-PFA than ostial-PFA (94% vs. 87%) but not statistically significant (p = 0.68). No organized atrial tachycardias (ATs) were observed. Ostial-PFA patients more often underwent re-ablation due to recurrent AF episodes. WACA-PFA is feasible and resulted in significantly wider lesion sets than ostial-PFA. Concomitant posterior LA wall isolation occurred as an epiphenomenon in the majority of patients. The WACA approach was associated with neither increased procedure and fluoroscopy times nor statistically significant differences in 1-year rhythm outcome. ATs were absent.

Pulsed field ablation based pulmonary vein isolation utilizing a simplified approach

Abstract Funding Acknowledgements Type of funding sources: None. Background Pulsed field ablation (PFA) is a novel non-thermal energy source with promising safety and efficacy advantages compared to standard ablation technologies. Purpose We aimed to develop a safe, effective and fast pulmonary vein isolation (PVI) utilizing a single shot PFA catheter via a single femoral vein puncture and a venous closure system approach. Methods Forty-eight consecutive AF patients underwent first-time PVI via PFA under deep sedation. A single ultrasound guided femoral vein puncture and a single transseptal puncture was utilized for left atrial access. After pulmonary vein (PV) angiography eight pulse trains (2kV/2.5 sec, bipolar, biphasic, each 4x basket/flower configuration) were delivered to each PV. Extra pulse trains in the flower configuration (8x) were added to the posterior wall for very wide antral circumferential ablation (vWACA). Continuous intraluminal esophageal temperature (TESO) was monitored with a s-shaped esophageal temperature probe. A venous closure system was utilized on the single access site. A Donati suture was performed. The pressure bandage was removed after 1h. Results Patients (mean age: 64 +/-11 years) presented with AF (paroxysmal 58% or persistent AF (42%). A total of 192 PV were identified and isolated via PFA (100%). A mean of 40 pulse trains for PVI and vWACA have been used. The mean procedural time was 27 +/- 7 minutes, the mean catheter dwell time was 14 +/- 6 minutes and the median fluoroscopy time was 6 +/- 2 minutes. No relevant esophagus temperature rise occurred. One patient (2%) experienced a transient phrenic nerve palsy which recovered until the end of the procedure. Two patients (4%) experienced a superficial bleeding which was treated by a figure of eight suture. No severed hematoma, transfusion or intervention was necessary. No pericardial effusion or tamponade occurred. Conclusion The combination of a single vein single transseptal puncture approach resulted in a 100% rate of acute PVI and an extraordinary fast procedure and dwell time. The rate of periprocedural complications was low.

Photonic-assisted multi-format dual-band microwave signal generator without background noise.

We report a photonic approach to generate background-free multi-format dual-band microwave signals based on a single modulator, which is suitable for high-precision and fast detection of radars in complex electromagnetic environments. By applying different radio-frequency signals and electrical coding signals to the polarization-division multiplexing Mach-Zehnder modulator (PDM-MZM), the generation of dual-band dual-chirp signals or dual-band phase-coded pulse signals centered at 10 and 15.5 GHz is experimentally demonstrated. Furthermore, by choosing an appropriate fiber length, we verified that the generated dual-band dual-chirp signals are not affected by chromatic-dispersion induced-power fading (CDIP); meanwhile, by autocorrelation calculations, we got high pulse compression ratios (PCRs) of 13 of the generated dual-band phase-encoded signals, showing that the generated phase-encoded signals can be emitted directly without extra pulse truncation operation. The proposed system features a compact structure, reconfigurability and polarization independence, which is promising for multi-functional dual-band radar systems.

High-pure AlN crystalline thin films deposited on GaN at low temperature by plasma-enhanced ALD

Aluminum nitride (AlN) thin film has been considered one of the most promising candidates for gate insulating layer of GaN-based HEMT devices. To reach the highest performance of devices, it is still necessary to further reduce the defect density at the interface and within the film of the AlN insulating layer, as well as to develop low temperature processes for good compatibility. In this work, by adopting an extra Ar plasma pulse in the plasma-enhanced atomic layer deposition (PEALD) process cycle, crystalline AlN thin films were deposited on Gallium Nitride (GaN) substrates at a temperature as low as 200 °C and have almost no C and O contaminations detectable in the films. The atomic structure, surface morphology and chemical component of the AlN films have been characterized systemically, showing the great potential of application in GaN devices as gate insulating or passivation layers.

Impact of very wide antral pulmonary vein isolation on esophageal temperature changes during pulsed field ablation

Abstract Funding Acknowledgements Type of funding sources: None. Background Esophageal thermal injury (ETI) is a serious drawback of available energy sources for atrial fibrillation (AF) ablation, especially on the posterior left atrial (LA) wall. Pulsed field ablation (PFA) is a novel non-thermal energy source with promising safety advantages over existing methods due to its unique myocardial tissue specificity sparing the esophagus. Objective To evaluate esophageal temperature changes during very wide antral pulmonary vein isolation (PVI) using the PFA system. Methods Thirteen consecutive AF patients (62% with paroxysmal AF; age: 61 years; 70% male) underwent first-time PFA under deep sedation. Eight pulse trains (2kV/2.5 sec, bipolar, biphasic, 4x basket/flower configuration each) were delivered to each pulmonary vein (PV). Extra pulse trains in the flower configuration were added for very wide antral circumferential ablation (vWACA). Continuous intraluminal esophageal temperature (TESO) was monitored with an S-shaped esophageal temperature probe. Results A median of 32 (IQR 32;32) and 8 (IQR 8;9) pulse trains for PVI and vWACA with a procedural time and catheter dwell time of 67 min (IQR 61-69) and 17 min (IQR 16-18) were applied. PFA with vWACA resulted in consecutive posterior LA wall isolation in 11/13 patients. Fluoroscopically, the esophagus coursed near the right PVs in 2/13, left PVs in 8/13 and mid-posterior wall position in 3/13 patients. Maximum TESO increase from baseline was 0.8 ±0.9 °C. However, no clinically relevant TESO changes occurred (Table 1). On short-term, all patients remained asymptomatic for sore throat, cough, or other symptoms potentially related to ETI. No esophago-duodenoscopy was necessary. Conclusion PFA of the PVs and lesion extension to the posterior LA wall demonstrated clinically non-significant TESO changes and has the potential to eliminate the risk of a thermal damage to the esophagus.

Comparison of ostial versus very wide antral circumferential pulmonary vein isolation using pulsed field ablation

Abstract Funding Acknowledgements Type of funding sources: None. Background Pulmonary vein isolation (PVI) is the gold standard for first-time atrial fibrillation (AF) ablation procedures. Wide antral circumferential ablation (WACA) in comparison to ostial PVI has been attributed to an improved rhythm outcome after AF ablation. Pulsed field ablation (PFA) is a novel energy source with promising safety and efficacy advantages over existing ablation methods due to its unique myocardial tissue specificity. Feasibility of PFA for very WACA has not been investigated so far. Objective To evaluate procedural characteristics and lesion formation during wide antral circumferential PVI in comparison to ostial PVI using a PFA system. Methods Thirty-seven consecutive AF patients underwent first-time PFA under deep sedation. Patients eighter received ostial (ostial group; N = 15: 66 % paroxysmal AF; age: 69 years; 66 % male) or very wide antral (vWACA group; N = 22: 59 % paroxysmal AF; age: 62 years; 73 % male) PFA. Pre and post ablation LA voltage maps were acquired using a 20-pole spiral catheter together with a 3-dimensional electroanatomic mapping system (voltage cutoff ≤0.5 mV). On post ablation maps, lesion size by encircling the ablated area was measured. In all patients, 8 pulse trains (2kV/2.5 sec, bipolar, biphasic, 4x basket/flower configuration each) were delivered to each pulmonary vein (PV). In the vWACA-group, extra pulse trains in flower configuration were added to each PV in a wide antral position continuous intraluminal esophageal temperatures (TESO) were monitored with an S-shaped esophageal temperature probe. Results A median of 8 [IQR 8;8] and 10 [IQR 10;11] pulse trains per PV for ostial and vWACA PVI were applied. vWACA PFA resulted in significant larger lesion formation (47.3 cm2 [IQR 39.1; 52.0]) in comparison to ostial PFA (35.5 cm2 [IQR 30.3; 38.1], p=0.013) with consecutive posterior LA wall isolation in 19/22 (86 %) patients (Figure 1). In the vWACA group, median TESO increased by 0.7 °C (TESOmax 36.5 °C [IQR 36.0;36.9]). However, the vWACA approach was not associated with a significant increase in procedure time, sedation dosage or exposure to radiation. Conclusion Very wide antral circumferential PFA of the PVs is feasible and was associated with significant larger lesion formation in comparison to conventional ostial PFA. Concomitant posterior LA wall isolation occurred in the majority of patient and did not result in a clinically significant increase of intraluminal esophageal temperatures, procedure time, sedation and radiation dosage.

Fast high-fidelity geometric gates for singlet-triplet qubits

Geometric gates that use the global property of the geometric phase is believed to be a powerful tool to realize fault-tolerant quantum computation. However, for singlet-triplet qubits in semiconductor quantum dot, the low Rabi frequency of the microwave control leads to overly long gating time, and thus the constructing geometric gate suffers more from the decoherence effect. Here we investigate the key issue of whether the fast geometric gate can be realized for singlet-triplet qubits without introducing an extra microwave-driven pulse, while maintaining the high-fidelity gate operation at the same time. We surprisingly find that both the single- and two-qubit geometric gates can be implemented via only modulating the time-dependent exchange interaction of the Hamiltonian, which can typically be on the order of $\sim$GHz, and thus the corresponding gate time is of several nanoseconds. Furthermore, the obtained geometric gates are superior to their counterparts, i.e., the conventional dynamical gates for singlet-triplet qubits, with a relatively high fidelity surpassing $99\%$. Therefore our scheme is particularly applied to singlet-triplet qubits to obtain fast and high-fidelity geometric gates. Our scheme can also be extended to other systems without a microwave drive.

Immunosuppressive regimens on conversion of cytomegalovirus infection to disease in liver transplant recipients.

Cytomegalovirus (CMV) disease is one of the most common infectious complications after liver transplantation. It is the cause of numerous morbidity and mortalities. Intensity of immunosuppression defined as overall immunosuppressive drug dosage seems to affect infectious complications. The main purpose of this study is to investigate the intensity of immunosuppression on conversion of CMV infection to disease in this population. In this cross-sectional study, we retrospectively evaluated and analyzed the data of all recipients who underwent orthotopic liver transplantation (OLT) between March 2014 and March 2016 and had positive serum PCR for CMV after transplantation in follow- up course. Of 134 recipients, only 66 adult liver transplant recipients were eligible to be studied. Multiple variables such as MELD score, cold ischemic time, warm ischemic time, operative data, immunosuppressive drugs and regimen, plasma CMV viral load, donor and recipient CMV IgG serostatus were recorded and analyzed. of the 66 patients, 50 (76%) had CMV infection and 16 (24%) had disease. There was significant association between donor CMV IgG serostatus, extra corticosteroid pulse therapy, acute cellular rejection, serum tacrolimus level and conversion of CMV infection to CMV disease (P=0.005, 0.001, 0.031, 0.031). It seems that the intensity of immunosuppression has influence on conversion rate of CMV infection to disease in liver recipients.

Reduction of Carbon Impurities in Aluminum Nitride from Time-Resolved Chemical Vapor Deposition Using Trimethylaluminum

Aluminum nitride (AlN) is a semiconductor with a wide range of applications from light-emitting diodes to high-frequency transistors. Electronic grade AlN is routinely deposited at 1000 °C by chemical vapor deposition (CVD) using trimethylaluminum (TMA) and NH3, while low-temperature CVD routes to high-quality AlN are scarce and suffer from high levels of carbon impurities in the film. We report on an atomic layer deposition-like CVD approach with time-resolved precursor supply where readsorption of methyl groups from the AlN surface is suppressed by the addition of an extra pulse, H2, N2, or Ar, between the TMA and NH3 pulses. The suppressed readsorption allowed deposition of AlN films with a carbon content of 1 at. % at 480 °C. Kinetic and quantum-chemical modeling suggests that the extra pulse between TMA and NH3 prevents readsorption of desorbing methyl groups terminating the AlN surface after the TMA pulse.

The impact of TMS and PNS frequencies on MEP potentiation in PAS with high-frequency peripheral component.

Paired associative stimulation (PAS) combines transcranial magnetic stimulation (TMS) and peripheral nerve stimulation (PNS) to induce plastic changes in the corticospinal tract. PAS employing single 0.2-Hz TMS pulses synchronized with the first pulse of 50–100 Hz PNS trains potentiates motor-evoked potentials (MEPs) in a stable manner in healthy participants and enhances voluntary motor output in spinal cord injury (SCI) patients. We further investigated the impact of settings of this PAS variant on MEP potentiation in healthy subjects. In experiment 1, we compared 0.2-Hz vs 0.4-Hz PAS. In experiment 2, PNS frequencies of 100 Hz, 200 Hz, and 400 Hz were compared. In experiment 3, we added a second TMS pulse. When compared with 0.4-Hz PAS, 0.2-Hz PAS was significantly more effective after 30 minutes (p = 0.05) and 60 minutes (p = 0.014). MEP potentiation by PAS with 100-Hz and 200-Hz PNS did not differ. PAS with 400-Hz PNS was less effective than 100-Hz (p = 0.023) and 200-Hz (p = 0.013) PNS. Adding an extra TMS pulse rendered PAS strongly inhibitory. These negative findings demonstrate that the 0.2-Hz PAS with 100-Hz PNS previously used in clinical studies is optimal and the modifications employed here do not enhance its efficacy.

Observation of Postoperative Analgesia in Elderly Patients with PFNA By Routine Pulsed Lumbar Plexus Administration

Objective to observe the postoperative analgesia of elderly patients with PFNA by pulsed lumbar plexus administration. Methods: 90 patients with PFNA postoperative analgesia were selected and divided into three groups on average. The first group, 30 routine PCIA. The second group received PCEA analgesia after spinal anesthesia. In the third group, the intraoperative lumbar plexus nerve block was completed and the anesthetic catheter was indwelling. The drug administration mode was programmed pulse administration without background dose. The pain index, movement tissue index and the incidence of various adverse reactions were observed after PFNA. Results the pain score of peripheral nerve block program pulse group was significantly lower than that of general anesthesia group, the incidence of motor tissue was lower than that of epidural group, and the incidence of side effects was lower than that of general anesthesia group and epidural group. Conclusion patients with PFNA is mostly elderly patients with varying degrees of system disease and organ function degradation, extra week nerve block program pulse to VAS score is lower and less motor block, fewer side effects, is PFNA more effective postoperative analgesia mode, you can reply as soon as possible to the patient's activity ability, improve the prognosis of patients.

Control Valve Stiction Compensation - Part I: A New Method for Compensating Control Valve Stiction

Valve stiction is a hidden menace in process control loops. The presence of stiction in control valves limits the control loop performance. Compensation of its effect is beneficial before the sticky valve can be sent for maintenance. This work is the first of a two part study on control valve stiction compensation. This part proposes a novel stiction compensation method while the second part compares the performance of this proposed stiction compensation method with some of other compensation methods appeared in literature. The proposed compensator is developed based on reduction of control action and addition of an extra pulse of finite energy as required. A method for estimating an appropriate parameter for reducing controller action has been developed. The proposed stiction compensator has been extensively evaluated using MATLAB Simulink environment. The compensator has also been implemented in a pilot plant experimental set-up. It has been found to be successful in removing valve stiction induced osci...

Study Title: Clinical Outcomes of Prolensa (Bromfenac Ophthalmic Solution) 0.07% QD vs. Ilevro (Nepafenac Ophthalmic Suspension) 0.3% QD With Extra (Pulse) Dose on Day of Surgery for Treatment of Ocular Inflammation Associated With Cataract Surgery in a Randomized, Single Masked Clinical Trial

Study Title: Clinical Outcomes of Prolensa (Bromfenac Ophthalmic Solution) 0.07% QD vs. Ilevro (Nepafenac Ophthalmic Suspension) 0.3% QD With Extra (Pulse) Dose on Day of Surgery for Treatment of Ocular Inflammation Associated With Cataract Surgery in a Randomized, Single Masked Clinical Trial

Detection of extra pulses in synthesized glottal area waveforms of dysphonic voices

Background and objectivesThe description of production kinematics of dysphonic voices plays an important role in the clinical care of voice disorders. However, high-speed videolaryngoscopy is not routinely used in clinical practice, partly because there is a lack of diagnostic markers that may be obtained from high-speed videos automatically. Aim of the study is to propose and test a procedure that automatically detects extra pulses, which may occur in voiced source signals of pathological voices in addition to cyclic pulses. Material and methodsGlottal area waveforms (GAW) are synthesized and used to test a detector for extra pulses. Regarding synthesis, for each GAW a cyclic pulse train is mixed with an extra pulse train, and additive noise. The cyclic pulse trains are varied across GAWs in terms of fundamental frequency, pulse shape, and modulation noise, i.e., jitter and shimmer. The extra pulse trains are varied across GAWs in terms of the height of the extra pulses, and their rates of occurrence. The energy level of the additive noise is also varied. Regarding detection, first, the fundamental frequency is estimated jointly with the cyclic pulse train waveform, second, the modulation noise is estimated, and finally the extra pulse train waveform is estimated. Two versions of the detector are compared, i.e., one that parameterizes the shapes of the cyclic pulses, and one that uses unparameterized pulse shape estimates. Two corpora are used for testing, i.e., one with 100 GAWs containing random extra pulses, and one with 25 GAWs containing extra pulses in the closed phases of each glottal phase representing subharmonic voices. Results and discussionWith pulse shape parameterization (PSP) a maximum mean accuracy of 88.3% is achieved when detecting random extra pulses. Without PSP, the maximum mean accuracy reduces to 82.9%. Detection performance decreases if the energy level of additive noise is higher than −25 dB with respect to the energy of the cyclic pulse train, and if the irregularity strength exceeds 0.1. For bicyclic, i.e., subharmonic voices, the approach fails without PSP, whereas with PSP, a mean sensitivity of 87.4% is achieved for subharmonic voices. ConclusionA synthesizer for GAWs containing extra pulses, and a detector for extra pulses are proposed. With PSP, favorable detector performance is observed for not too high levels of additive noise and irregularity strengths. In signals with high noise levels, the detector without PSP outperforms the other one. Detection of extra pulses fails if irregularity strength is large. For subharmonic voices PSP must be used.

Subcycle Terahertz Nonlinear Optics.

The nonlinear interaction of subcycle electromagnetic radiation with matter is the current frontier in ultrafast nonlinear optics and high-field physics. Here, we investigate nonlinear optical effects induced by intense, subcycle terahertz radiation in a doped semiconductor. We observe a truncation of the half-cycle terahertz pulse and an emission of high-frequency terahertz photons. We attribute our observations to the abrupt current drop caused by strong intervalley scattering effects. By adding an extra half-cycle terahertz pulse with opposite polarity, we monitor the evolution of the nonlinear carrier dynamics during a quasi-single-cycle pulse. Our results demonstrate the differences between nonlinear effects for subcycle and multicycle terahertz pulses. It also suggests a new approach to subcycle control of terahertz waveforms, and the generation of high-order terahertz harmonics could be realized by using multicycle pulses.

Optimization of pulsed voltage waveform for electrohydrodynamic jetting on-demand

For electrohydrodynamic jetting-on-demand, the conventional positive voltage pulse superposed by a dc bias voltage have been widely used. Once this voltage pulse was induced, the meniscus at the nozzle tip oscillated and its volume changed owing to the fluid supplied through the nozzle as well. To increase the maximum frequency for consistent jetting, it is desirable to minimize these phenomena. When the oscillation amplitude was sufficiently small to assume the occurrence of linear behavior and no jetting, the above phenomena could be well explained by using a harmonic oscillator model and a one-dimensional flow model. Based on this physical understanding, the root-polar voltage waveform was proposed and could significantly decrease the change in meniscus height; thus it was possible to increase the maximum frequency for consistent jetting. In addition, the residual oscillation could be also suppressed using an extra voltage pulse waveform. Furthermore, the root-polar voltage waveforms with a minus voltage pulse as well as a positive one could be demonstrated; thus it was shown that the root-polar voltage waveform could be implemented into ac-pulse modulated EHD jetting as well.

Chronological clinicopathological characterization of rapidly progressive alopecia areata resistant to multiple i.v. corticosteroid pulse therapies: An implication for improving the efficacy.

Intravenous corticosteroid pulse therapy (pulse therapy) has been reported to be effective for rapidly progressive alopecia areata (RP-AA). Mostly, a single 3-day administration of corticosteroid (methylprednisolone 500 mg/day) has been performed in Japan; however, to what extent additional administrations improve the outcome has not been fully elucidated. To assess the advantage of repeating the pulse therapy to RP-AA cases refractory to the initial intervention, retrospective clinicopathological analysis was performed. Detailed chronological analysis was conducted in eight cases (one man and seven women; average age, 38.3 ± 10.4 years) demonstrating total scalp hair loss 3 months after the first pulse therapy and treated with additional rounds of the pulse therapy. All cases manifested total hair loss, scalp edema, itch or pain on the scalp after the initial intervention. Histopathological analyses of affected lesions prior to additional pulse therapies revealed persisting dense perifollicular lymphocytic inflammation in all cases. Interestingly, such inflammatory change tended to be severer when compared with previously reported pulse therapy good responders. Extra pulse therapy resulted in partial regrowth of terminal hairs in three out of eight cases, but all of them experienced relapse in the long run. The literature review also suggested limited efficacy of repeating pulse therapy to severe AA cases. These findings suggested that the efficacy of currently conducted repetitive pulse therapy is limited in RP-AA cases with extensive perifollicular inflammation and resistant to the initial pulse therapy. Modulation of the dose and the interval of intervention, in combination with alternative approaches, may be required to achieve a successful outcome.

A novel electric-field-accelerated ion-sieve membrane system coupling potential-oscillation for alkali metal ions separation

A novel electric-field-accelerated ion-sieve membrane (EISM) system with potential-oscillation was set up for the selective separation of the alkali metal ions. The ion-sieve membrane was fabricated by coating a polypyrrole/polystyrenesulfonate composite on the stainless steel wire mesh (PPy/PSS/SSWM). In the EISM system, an external electric filed was applied by introducing a constant cell voltage on the two sides of the ion-sieve membrane to accelerate the directed transport of target ions through the membrane. Meanwhile, an extra pulse potential was applied on the PPy/PSS/SSWM membrane to adjust the ion binding ability of the PPy/PSS composite toward cations. As such, an enhanced “ion sieving effect” of the EISM system was achieved through the synergistic function of the constant cell voltage and potential oscillation, which resulted in the rapid transport of target cation across the membrane in a “leap-frogging” way. It is found that when an extra pulse potential of ±1.0 V (pulse width of 60 s) was applied on the EISM, the permeation flux of K+ ions was increased by 7.42-fold with a constant cell voltage of 5 V. The permselectivities of the PPy/PSS/SSWM membrane for K+/Li+ and K+/Cs+ reached 3.29 and 3.45 respectively based on the optimized amplitude (±1.0 V) and frequency (pulse width of 60 s) of pulse potential.